The present invention is directed to cable splice enclosures and particularly enclosures of the type employing immersion of the splice in a body of sealant.
Utility and communication lines have traditionally been constructed above ground. However, governmental requirements and customer preference have resulted in more and more below ground installations. It has been found that the below ground installations are subject to a far harsher environment requiring a more sophisticated protection system for the encased conductors. The problems associated with underground systems become particularly acute where a break in the conductor is required. As a result, the utility and communications industry has endeavored to develop clossures for these necessary splices which are able to provide reliable, long-term protection of the encased conductors. A number of systems have been found to be relatively successful in preventing moisture intrusion and corrosion and in providing structural strength needed to protect underground splices. However, many of these devices have been found to be difficult to assemble or unsuited for a wide range of applications.
To further elaborate on a major problem which has existed in the fabrication of underground splice enclosures, increased labor requirements coupled with a decrease in the availability of skilled technicians have resulted in a loss in the reliability of underground systems because of improper initial assembly. On the other hand, less complicated systems more suited to the available skill levels in the industry have been found to be less reliable and/or more expensive. One device by which reliability has been maintained and both cost and complexity of assembly have been reduced is the use of a container filled with the body of sealant into which the exposed conductors can be permanently immersed. Two such devices employing this sealing mechanism are disclosed in U.S. Pat. Nos. 4,039,742 and 4,053,704, assigned to the assignee of the present invention and incorporated herein by reference.
The device disclosed in U.S. Pat. No. 4,039,742 includes a vial of sealant into which the exposed splice is immersed. The cables associated with the splice were first assembled with a cap, a rigid clamping mechanism and an enclosing sleeve. This assembly was then forced into the sealant contained within the vial. It was intended that the sleeve, the rigid clamp and the cap would provide adequate structural protection for the insertion of the splice into the resisting body of sealant. In U.S. Pat. No. 4,053,704, a cap was devised which provided grooves for the incoming cables and was capable of being threaded onto a vial containing the body of sealant. This second device was primarily designed for relatively small splices such as would be encountered in an access telephone line to a residence.
Some difficulties have been encountered even with the total immersion mechanism for protecting cable splices. With larger cables and increased numbers of pairs, the displacement and forces imposed on each pair increase as a consequence of insuring that a larger splice bundle is adequately immersed. As a result, distortion and breakage of pairs can occur during immersion of the splice bundle. Furthermore, with large splices, greater force is required in immersing the splice in the sealant. Air passages through the sealant also become more likely. As a result, the need for skill and care in assembling such splice cases increases with the size of the case.